Abstract: To characterize the function of BpMADS12, a 1 750 bp flanking sequence upstream of the translation initiation codon was cloned, and several putative cisregulatory elements were deciphered from the promoter sequence of BpMADS12 using PLACE and PlantCARE web tools, and constructed into vector pBI101, and was transferred into Arabidopsis thaliana, then investigated the expression pattern and drought stress response via histechemical GUS staining. The results showed that flowering, multiple hormoneresponsive and droughtresponsive elements were predicted in the promoter region. Histechemical GUS staining showed that the BpMADS12 promoter expressed in all tissues and organs during reproductive phase, such as roots, floral leaves, petals, stamens, pistils, seeds, and so on, instead of vegetative phase; and the GUS expression was downregulated in transgenetic Arabidopsis thaliana after PEG stress. In conclusion, BpMADS12 participates in biological processes of flowering, hormone response, drought stress response, and regulates the development of all tissues and organs during the generative growth phase to some extent, and drought responsive pathway negatively.